Wasp spider foreign exchange programme shows shifting heat tolerance

By analysing the genetic diversity and distribution of the wasp
spider (Argiope
bruennichi) geneticists at the Max Planck Institute for
Evolutionary Biology have pinned the initial shift in the spiders'
range to the 1930s, occurring "in parallel with the onset of global
warming".

The research, which sampled historical specimens from museum
collections as well as contemporary spider populations, noted that
after this initial change interbreeding allowed the spiders to
gradually shift their natural temperature preferences and penetrate
further and further north.

To test the theory, the researchers transplanted spiders from
northern populations to southern, Mediterranean climes and vice
versa -- the arachnid equivalent of a foreign exchange program. The
northern spiders exhibited signs of heat stress during their
sojourn while the southern spiders couldn't survive the northern
chill.

"Global warming could have facilitated the initial admixture of
populations and this resulted in genetic lineages with new habitat
preferences," said the study's author, Henrik Krehenwinkel.